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Mission 10: Data Quality

Learning Objective

Learn how to assess the quality of your data through comprehensive metrics and understand what makes data high quality.


Dataset

Download the required dataset: new_table_cars.xlsx


Step-by-Step Instructions

1. Open Your Dataset

First, open the data you want to analyze.

2. Access Analytics

Click on the analytics button to access data quality tools.

Analytics Button

The analytics button

3. View Table Overview

After clicking analytics, you'll see the table overview.

Table Overview

Table overview page

4. Navigate to Data Quality

Click "Data Quality" in the top menu to view quality metrics.


Data Quality Metrics

Quality Metrics

Indicators for various data quality metrics

Understanding the Metrics

  • Consistency - How consistent is the data? Are there columns that mix different data types?
  • Completeness - How complete is the data? Are there missing values?
  • Outliers - Are there many outliers in the data?
  • Uniqueness - Is there redundancy in the data?
  • Total - A combined score providing an overall quality overview

Note

For each metric, a higher score indicates better data quality.


Data Cleaning Options

Cleaning Options

Click on cleaning option buttons to access the data transformer tool

The data transformer is a powerful tool that helps you improve data quality and get the most out of your datasets.


Quality Score History

Quality History

The combined data quality score over time - updates as the table is modified

Track how your data quality improves as you clean and refine your datasets.


Best Practices

  • Regular monitoring - Check data quality metrics regularly
  • Address completeness first - Missing values often have the biggest impact
  • Review consistency - Ensure data types are appropriate for each column
  • Handle outliers carefully - Understand if they're errors or valid extreme values
  • Eliminate redundancy - Remove duplicate rows to improve uniqueness

Summary

You've successfully learned how to:

✓ Access the data quality analytics dashboard

✓ Understand key data quality metrics

✓ Interpret consistency, completeness, outliers, and uniqueness scores

✓ Use cleaning options to improve data quality

✓ Track quality improvements over time


Well done! Now let's move on to the next mission!